Characteristics and function of cell organelles

microvilli (characteristic)

extensive folding of the cell membrane

microvilli (function)

increase surface area for absorption

cell membrane (characteristics)

bilayer of phospholipid molecules with inserted proteins

cell membrane (function)

acts as a gateway for and barrier to movement of material between the interior of the cell and the extracellular fluid

cytosol (characteristics)

semi-gelatinous substance

cytosol (function)

contains dissolved nutrients, ions, wastes, insoluble inclusions; suspends the organelles

centrioles (characteristics)

bundles of microtubules

centrioles (function)

direct movement of DNA during cell division

lysosomes and peroxisomes (characteristics)

membrane-bound vesicles filled with enzymes

lysosomes and peroxisomes (function)

digest bacteria, old organelles; metabolize fatty acids

mitochondrion (characteristics)

double wall with central matrix

mitochondrion (function)

produces most of cell's ATP

Golgi apparatus (characteristics)

hollow membranous sacs

Golgi apparatus (function)

modify and package proteins

nucleus (characteristics)

central lumen with a two-membrane outer envelope with pores

nucleus (function)

contains DNA to direct all functions of the cell

nucleolus (characteristics)

region of DNA, RNA and protein

nucleolus (function)

contains the genes that direct synthesis of ribosomal RNA

rough endoplasmic reticulum (characteristics)

membrane tubules that are continuous with the outer nuclear membrane; edged with ribosomes

rough endoplasmic reticulum (function)

site of protein synthesis

smooth endoplasmic reticulum (characteristics)

same as rough ER without ribosomes

smooth endoplasmic reticulum (function)

synthesis of fatty acids, steroids and lipids

ribosomes (characteristics)

granules of RNA and protein

ribosomes (function)

assemble amino acids into proteins

microtubules and microfilaments (characteristics)

protein fibers

microtubules and microfilaments (function)

provide strength and support; enable cell motility; transport